And it would help explain a lifetime of torment — from uncontrollable rages, wild mood swings, stints in mental health hospitals, doomed relationships, binge drinking and class A drugs before her suicide bid.

Ali, who has now written a book about living with the condition called Beautiful Chaos, says: “At eight years old I was experiencing mood fluctuations that were beyond my comprehension.

“At that time, I never tried to figure out why it was happening. Why would I? It was just me. I was a weirdo.”

Raised in Glasgow’s leafy Bearsden by nurse mum Pam and architect dad Iain, Ali was the middle daughter of three sisters including Cath and Val.

She admits: “It was a lovely middle-class upbringing.

“My folks even bought me a horse in my teens. It was a very privileged upbringing, but I wasn’t to know then that mental health issues are completely indiscriminate.”

After finding she had a flair for presentations at uni, she made a show reel which saw her land her first TV job in 1994 — hosting the STV kids’ show Skoosh for four years.

She recalls: “One week I’d be presenting a report from a zoo with a 6ft python draped around my neck.

“Then the next I’d be interviewing Boyzone — which was great as I really fancied Ronan Keating. I bought my first flat and my car and had a great social life. But inside it was just hell. I was either hugely depressed or ecstatic.”

She admits she started to go off the rails. She explains: “I had no self-worth whatsoever, and as a result, my judgment was severely lacking.

“I’d date a guy for a couple of weeks, fall desperately in love, then move on to someone else. I could just about manage to remember their name during their two-week window.

“I also began dabbling with recreational drugs. It started with speed and ecstasy, before I moved onto cocaine. The binge drinking started around the same time.”

Amazingly, the chaotic lifestyle didn’t affect her career — which included a stint on Daybreak.

At 27, she hit the lowest point in her life in Spain, but there were still many pitfalls ahead. She says: “It wasn’t long after Spain that I ended up in a private mental health hospital.

“But I was always diagnosed with depression and anxiety so was always on and off anti- depressants and sent on my way.”

Ali suffered another major breakdown as she was about to audition as host of Rangers TV. She says: “I was back inside the mental health hospital for six weeks. I went out on day release to do my interview for Rangers TV, got the job then went back to the hospital. Of course I didn’t tell them I was just popping back to the mental health unit.”